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J Contreras

Publications and source records attributed to J Contreras.

80 records · Page 5Linked to original sources
PubMedDate not supplied

[Thoracic actinomycosis].

Thoracic actinomycosis was identified in a 14 year old girl. The disease is infrequent in children and diagnosis is difficult. The occurrence of a protracted pulmonary lesion, together with osteomyelitis of several ribs and by fistulae formation in the chest wall, with production of characteristic "sulfur granules", were the key elements to suspect the right diagnosis, which was confirmed by a bacteriological and histological studies. Treatment with high doses of intravenous penicillin, 3 million U four times a day for 4 weeks, followed by long term oral therapy with the same drug was done, with remission of pulmonary, osseous and cutaneous lesions.

Actinomycosis↗
PubMedDate not supplied

Delayed hypersensitivity to beta-lactams.

We present nine patients with delayed allergic reactions to beta-lactams. Four of them developed reactions to ampicillin; the diagnostic studies suggested the involvement of a type IV hypersensitivity mechanism to an antigenic determinant in the side-chain structure, with intradermal and patch tests positive to ampicillin but good tolerance to benzylpenicillin. Three patients showed delayed hypersensitivity reactions to benzylpenicillin (positive delayed skin tests and/or challenges). Arthus-type reactions were seen in two other patients. Specific IgE of uncertain relationship to benzylpenicillin and ampicillin was later detected in four cases.

Adult↗
PubMedDate not supplied

[Neoadjuvant treatment with cisplatin, 5-FU and folinic acid in advanced head and neck cancer].

From May to February 1992, 32 patients diagnosed as advanced cancer of the head and neck were included in a program of neoadjuvant treatment with cisplatin, 5-FU, and folinic acid, followed by radiotherapy (45 at 70 Gy) and/or surgery. Twenty patients were considered fully evaluable; their global response rate was 75% (7 complete responses and 8 partial responses). Five patients had no appreciable response or progression. Radiotherapy after chemotherapy enhanced the response, yielding complete responses in 4 patients and partial response in 1. Toxicity was moderate, except for mucositis (9 cases grade 3-4), despite high doses of drugs and radiotherapy. Given the clinical results, this combination may be promising as a first-line treatment against advanced cancer of the head and neck.

Chemotherapy, Adjuvant↗
PubMedDate not supplied

Two cases of specific adverse reactions to systemic corticosteroids.

Although true allergic reactions due to systemic corticosteroid therapy are not frequent, they should be kept in mind since allergic reactions to this kind of therapy are possible. We report two cases of specific adverse reactions resulting from systemic corticosteroid therapy which were diagnosed by provocation tests. The corticosteroids involved in each case were paramethasone and betamethasone, and methyl-prednisolone in both of them. Additives and other corticosteroids were studied by skin tests and challenges, with negative results. The structures of paramethasone and betamethasone are similar, with a 16 carbon methyl group in both, and with a fluoride in the alpha position of the 6 carbon in paramethasone, and a fluoride in the beta position of the 9 carbon and a 6 carbon methyl group in betamethasone. Methyl-prednisolone differs from that of other corticosteroids in its 6 carbon methyl group. We report two cases of specific adverse reactions caused by corticosteroids. Positive challenge tests showed a possible immunologic hypersensitivity mechanism in both cases. The patients' reactions demonstrated cross-reactivity between methyl-prednisolone and the corticosteroids having a 16 carbon methyl group, and fluoride or methyl radicals on the 6 carbon.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Temporary and permanent restorations for fractured permanent teeth with immature apices: a clinical study.

Clinical and radiological studies of the fractured teeth of patients between seven and eleven years old were conducted to assess the use of permanent and immediate (emergency) techniques for reconstructing anterior permanent teeth with immature apices. The general hypothesis states that, given the physical and biocompatible properties of the materials used in the immediate (emergency) technique, there are no significant differences between the two techniques as far as pulp vitality and apical growth are concerned. A sample of fifty-six patients was selected. They had Class I, II or III fractures, for which permanent and immediate (emergency) techniques were used in equal numbers. Thermal, mechanical, and electrical tests were used to evaluate pulp vitality compared with the homologous tooth. Apical convergence was the radiological criterion used for determining the end of the radicular process. After one year, both techniques allow preservation of pulp vitality. Results show that, unlike the conventional technique (permanent), radicular formation was completed first in teeth reconstructed using the immediate (emergency) technique. Statistical analysis shows no definitive relationship between the technique used and completion of apical growth time (P > 0.05). In conclusion, comparison between the mediate (permanent) and immediate (emergency) techniques shows that the immediate (emergency) technique is an adequate alternative for reconstructing fractured teeth, because of the greater esthetic and functional advantages at the patient's disposal.

Biocompatible Materials↗